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Crosspoint/lib/Epub/Epub/parsers/ContentOpfParser.cpp
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#include "ContentOpfParser.h"
#include <FsHelpers.h>
#include <Logging.h>
#include <Serialization.h>
#include <XmlParserUtils.h>
#include <cctype>
#include "Epub/BookMetadataCache.h"
namespace {
constexpr char MEDIA_TYPE_NCX[] = "application/x-dtbncx+xml";
constexpr char MEDIA_TYPE_CSS[] = "text/css";
constexpr char MEDIA_TYPE_IMAGE_PREFIX[] = "image/";
constexpr char itemCacheFile[] = "/.items.bin";
bool startsWithImageMediaType(const std::string& mediaType) {
constexpr size_t prefixLen = sizeof(MEDIA_TYPE_IMAGE_PREFIX) - 1;
if (mediaType.size() < prefixLen) {
return false;
}
for (size_t i = 0; i < prefixLen; ++i) {
const char c = static_cast<char>(std::tolower(static_cast<unsigned char>(mediaType[i])));
if (c != MEDIA_TYPE_IMAGE_PREFIX[i]) {
return false;
}
}
return true;
}
} // namespace
bool ContentOpfParser::setup() {
parser = XML_ParserCreate(nullptr);
if (!parser) {
LOG_DBG("COF", "Couldn't allocate memory for parser");
return false;
}
XML_SetUserData(parser, this);
XML_SetElementHandler(parser, startElement, endElement);
XML_SetCharacterDataHandler(parser, characterData);
return true;
}
ContentOpfParser::~ContentOpfParser() {
destroyXmlParser(parser);
if (tempItemStore) {
tempItemStore.close();
}
const auto itemCachePath = cachePath + itemCacheFile;
if (Storage.exists(itemCachePath.c_str())) {
Storage.remove(itemCachePath.c_str());
}
}
size_t ContentOpfParser::write(const uint8_t data) { return write(&data, 1); }
size_t ContentOpfParser::write(const uint8_t* buffer, const size_t size) {
if (!parser) return 0;
const uint8_t* currentBufferPos = buffer;
auto remainingInBuffer = size;
while (remainingInBuffer > 0) {
void* const buf = XML_GetBuffer(parser, 1024);
if (!buf) {
LOG_ERR("COF", "Couldn't allocate memory for buffer");
destroyXmlParser(parser);
return 0;
}
const auto toRead = remainingInBuffer < 1024 ? remainingInBuffer : 1024;
memcpy(buf, currentBufferPos, toRead);
if (XML_ParseBuffer(parser, static_cast<int>(toRead), remainingSize == toRead) == XML_STATUS_ERROR) {
LOG_DBG("COF", "Parse error at line %lu: %s", XML_GetCurrentLineNumber(parser),
XML_ErrorString(XML_GetErrorCode(parser)));
destroyXmlParser(parser);
return 0;
}
currentBufferPos += toRead;
remainingInBuffer -= toRead;
remainingSize -= toRead;
}
return size;
}
void XMLCALL ContentOpfParser::startElement(void* userData, const XML_Char* name, const XML_Char** atts) {
auto* self = static_cast<ContentOpfParser*>(userData);
(void)atts;
if (self->state == START && (strcmp(name, "package") == 0 || strcmp(name, "opf:package") == 0)) {
self->state = IN_PACKAGE;
return;
}
if (self->state == IN_PACKAGE && (strcmp(name, "metadata") == 0 || strcmp(name, "opf:metadata") == 0)) {
self->state = IN_METADATA;
return;
}
if (self->state == IN_METADATA && strcmp(name, "dc:title") == 0) {
// Only capture the first dc:title element; subsequent ones are subtitles
if (self->title.empty()) {
self->state = IN_BOOK_TITLE;
}
return;
}
if (self->state == IN_METADATA && strcmp(name, "dc:creator") == 0) {
self->state = IN_BOOK_AUTHOR;
return;
}
if (self->state == IN_METADATA && strcmp(name, "dc:language") == 0) {
self->state = IN_BOOK_LANGUAGE;
return;
}
if (self->state == IN_PACKAGE && (strcmp(name, "manifest") == 0 || strcmp(name, "opf:manifest") == 0)) {
self->state = IN_MANIFEST;
if (!Storage.openFileForWrite("COF", self->cachePath + itemCacheFile, self->tempItemStore)) {
LOG_ERR("COF", "Couldn't open temp items file for writing. This is probably going to be a fatal error.");
}
return;
}
if (self->state == IN_PACKAGE && (strcmp(name, "spine") == 0 || strcmp(name, "opf:spine") == 0)) {
self->state = IN_SPINE;
if (!Storage.openFileForRead("COF", self->cachePath + itemCacheFile, self->tempItemStore)) {
LOG_ERR("COF", "Couldn't open temp items file for reading. This is probably going to be a fatal error.");
}
// Sort the (unconditionally-built) item index so every idref lookup uses binary
// search. Without this, small/medium manifests fell back to an O(spine × manifest)
// linear rescan of .items.bin per itemref (up to ~200ms/item at large scale).
if (!self->itemIndex.empty()) {
std::sort(self->itemIndex.begin(), self->itemIndex.end(), [](const ItemIndexEntry& a, const ItemIndexEntry& b) {
return a.idHash < b.idHash || (a.idHash == b.idHash && a.idLen < b.idLen);
});
self->useItemIndex = true;
LOG_DBG("COF", "Using fast index for %zu manifest items", self->itemIndex.size());
}
return;
}
if (self->state == IN_PACKAGE && (strcmp(name, "guide") == 0 || strcmp(name, "opf:guide") == 0)) {
self->state = IN_GUIDE;
// TODO Remove print
LOG_DBG("COF", "Entering guide state.");
if (!Storage.openFileForRead("COF", self->cachePath + itemCacheFile, self->tempItemStore)) {
LOG_ERR("COF", "Couldn't open temp items file for reading. This is probably going to be a fatal error.");
}
return;
}
if (self->state == IN_METADATA && (strcmp(name, "meta") == 0 || strcmp(name, "opf:meta") == 0)) {
bool isCover = false;
std::string coverItemId;
for (int i = 0; atts[i]; i += 2) {
if (strcmp(atts[i], "name") == 0 && strcmp(atts[i + 1], "cover") == 0) {
isCover = true;
} else if (strcmp(atts[i], "content") == 0) {
coverItemId = atts[i + 1];
}
}
if (isCover) {
self->coverItemId = coverItemId;
}
return;
}
if (self->state == IN_MANIFEST && (strcmp(name, "item") == 0 || strcmp(name, "opf:item") == 0)) {
std::string itemId;
std::string href;
std::string mediaType;
std::string properties;
for (int i = 0; atts[i]; i += 2) {
if (strcmp(atts[i], "id") == 0) {
itemId = atts[i + 1];
} else if (strcmp(atts[i], "href") == 0) {
href = FsHelpers::normalisePath(FsHelpers::decodeUriEscapes(self->baseContentPath + atts[i + 1]));
} else if (strcmp(atts[i], "media-type") == 0) {
mediaType = atts[i + 1];
} else if (strcmp(atts[i], "properties") == 0) {
properties = atts[i + 1];
}
}
// Record index entry for fast lookup later
if (self->tempItemStore) {
ItemIndexEntry entry;
entry.idHash = fnvHash(itemId);
entry.idLen = static_cast<uint16_t>(itemId.size());
entry.fileOffset = static_cast<uint32_t>(self->tempItemStore.position());
self->itemIndex.push_back(entry);
}
// Write items down to SD card
serialization::writeString(self->tempItemStore, itemId);
serialization::writeString(self->tempItemStore, href);
if (itemId == self->coverItemId) {
// Some EPUBs set meta name="cover" to an XHTML wrapper item.
// Only treat it as a cover image when the manifest media-type is image/*.
if (startsWithImageMediaType(mediaType)) {
self->coverItemHref = href;
} else {
LOG_DBG("COF", "Ignoring meta cover item '%s' with non-image media type: %s", itemId.c_str(),
mediaType.c_str());
}
}
if (mediaType == MEDIA_TYPE_NCX) {
if (self->tocNcxPath.empty()) {
self->tocNcxPath = href;
} else {
LOG_DBG("COF", "Warning: Multiple NCX files found in manifest. Ignoring duplicate: %s", href.c_str());
}
}
// Collect CSS files
if (mediaType == MEDIA_TYPE_CSS) {
self->cssFiles.push_back(href);
}
// EPUB 3: Check for nav document (properties contains "nav")
if (!properties.empty() && self->tocNavPath.empty()) {
// Properties is space-separated, check if "nav" is present as a word
if (properties == "nav" || properties.find("nav ") == 0 || properties.find(" nav") != std::string::npos) {
self->tocNavPath = href;
LOG_DBG("COF", "Found EPUB 3 nav document: %s", href.c_str());
}
}
// EPUB 3: Check for cover image (properties contains "cover-image")
if (!properties.empty() && self->coverItemHref.empty()) {
if (properties == "cover-image" || properties.find("cover-image ") == 0 ||
properties.find(" cover-image") != std::string::npos) {
self->coverItemHref = href;
}
}
return;
}
// NOTE: This relies on spine appearing after item manifest (which is pretty safe as it's part of the EPUB spec)
// Only run the spine parsing if there's a cache to add it to
if (self->cache) {
if (self->state == IN_SPINE && (strcmp(name, "itemref") == 0 || strcmp(name, "opf:itemref") == 0)) {
for (int i = 0; atts[i]; i += 2) {
if (strcmp(atts[i], "idref") == 0) {
const std::string idref = atts[i + 1];
std::string href;
bool found = false;
if (self->useItemIndex) {
// Fast path: binary search
uint32_t targetHash = fnvHash(idref);
uint16_t targetLen = static_cast<uint16_t>(idref.size());
auto it = std::lower_bound(self->itemIndex.begin(), self->itemIndex.end(),
ItemIndexEntry{targetHash, targetLen, 0},
[](const ItemIndexEntry& a, const ItemIndexEntry& b) {
return a.idHash < b.idHash || (a.idHash == b.idHash && a.idLen < b.idLen);
});
// Check for match (may need to check a few due to hash collisions)
while (it != self->itemIndex.end() && it->idHash == targetHash) {
self->tempItemStore.seek(it->fileOffset);
std::string itemId;
serialization::readString(self->tempItemStore, itemId);
if (itemId == idref) {
serialization::readString(self->tempItemStore, href);
found = true;
break;
}
++it;
}
} else {
// Fallback linear scan, only reached when the index is empty (no manifest
// items). The fast binary-search path above is used for all real manifests.
self->tempItemStore.seek(0);
std::string itemId;
while (self->tempItemStore.available()) {
serialization::readString(self->tempItemStore, itemId);
serialization::readString(self->tempItemStore, href);
if (itemId == idref) {
found = true;
break;
}
}
}
if (found && self->cache) {
self->cache->createSpineEntry(href);
}
}
}
return;
}
}
// parse the guide
if (self->state == IN_GUIDE && (strcmp(name, "reference") == 0 || strcmp(name, "opf:reference") == 0)) {
std::string type;
std::string guideHref;
for (int i = 0; atts[i]; i += 2) {
if (strcmp(atts[i], "type") == 0) {
type = atts[i + 1];
} else if (strcmp(atts[i], "href") == 0) {
guideHref = FsHelpers::normalisePath(FsHelpers::decodeUriEscapes(self->baseContentPath + atts[i + 1]));
}
}
if (!guideHref.empty()) {
if (type == "text" || (type == "start" && !self->textReferenceHref.empty())) {
LOG_DBG("COF", "Found %s reference in guide: %s", type.c_str(), guideHref.c_str());
self->textReferenceHref = guideHref;
} else if ((type == "cover" || type == "cover-page") && self->guideCoverPageHref.empty()) {
LOG_DBG("COF", "Found cover reference in guide: %s", guideHref.c_str());
self->guideCoverPageHref = guideHref;
}
}
return;
}
}
void XMLCALL ContentOpfParser::characterData(void* userData, const XML_Char* s, const int len) {
auto* self = static_cast<ContentOpfParser*>(userData);
if (self->state == IN_BOOK_TITLE) {
self->title.append(s, len);
return;
}
if (self->state == IN_BOOK_AUTHOR) {
if (!self->author.empty()) {
self->author.append(", "); // Add separator for multiple authors
}
self->author.append(s, len);
return;
}
if (self->state == IN_BOOK_LANGUAGE) {
self->language.append(s, len);
return;
}
}
void XMLCALL ContentOpfParser::endElement(void* userData, const XML_Char* name) {
auto* self = static_cast<ContentOpfParser*>(userData);
(void)name;
if (self->state == IN_SPINE && (strcmp(name, "spine") == 0 || strcmp(name, "opf:spine") == 0)) {
self->state = IN_PACKAGE;
self->tempItemStore.close();
return;
}
if (self->state == IN_GUIDE && (strcmp(name, "guide") == 0 || strcmp(name, "opf:guide") == 0)) {
self->state = IN_PACKAGE;
self->tempItemStore.close();
return;
}
if (self->state == IN_MANIFEST && (strcmp(name, "manifest") == 0 || strcmp(name, "opf:manifest") == 0)) {
self->state = IN_PACKAGE;
self->tempItemStore.close();
return;
}
if (self->state == IN_BOOK_TITLE && strcmp(name, "dc:title") == 0) {
self->state = IN_METADATA;
return;
}
if (self->state == IN_BOOK_AUTHOR && strcmp(name, "dc:creator") == 0) {
self->state = IN_METADATA;
return;
}
if (self->state == IN_BOOK_LANGUAGE && strcmp(name, "dc:language") == 0) {
self->state = IN_METADATA;
return;
}
if (self->state == IN_METADATA && (strcmp(name, "metadata") == 0 || strcmp(name, "opf:metadata") == 0)) {
self->state = IN_PACKAGE;
return;
}
if (self->state == IN_PACKAGE && (strcmp(name, "package") == 0 || strcmp(name, "opf:package") == 0)) {
self->state = START;
return;
}
}